Abstract
BackgroundUltraviolet-B (UV-B) radiation can affect several aspects ranging from plant growth to metabolic regulation. Maca is a Brassicaceae crop native to the Andes growing in above 3500 m of altitude. Although maca has been the focus mainly due to its nutraceutical properties, it remains unknown how maca plants tolerate to harsh environments, such as strong UV-B. Here, we present the first study that reports the physiological responses of maca plants to counteract and recover to repeated acute UV-B irradiation.ResultsIn detail, plants were daily exposed to acute UV-B irradiation followed by a recovery period under controlled conditions. The results showed that repeated acute UV-B exposures reduced biomass and photosynthetic parameters, with gradual senescence induction in exposed leaves, reduction of young leaves expansion and root growth inhibition. Negative correlation between increased UV-B and recovery was observed, with marked production of new biomass in plants treated one week or more.ConclusionsA differential UV-B response was observed: stress response was mainly controlled by a coordinated source-sink carbon allocation, while acclimation process may require UV-B-specific systemic defense response reflected on the phenotypic plasticity of maca plants. Moreover, these differential UV-B responses were also suggested by multifactorial analysis based on biometric and physiological data.
Highlights
Ultraviolet-B (UV-B) radiation can affect several aspects ranging from plant growth to metabolic regulation
Biometric analysis Maca plants exposed to UV-B irradiation showed a clear reduction of total fresh weight (FW) in comparison to the control which was highly pronounced with the irradiation time (Fig. 1a)
Similar pattern was observed when the content of total soluble sugars (TSS) was expressed per FW of corresponding organ (Fig. 2b), which was tightly correlated with the steady reduction in FW of treated plants with respect to the control (Fig. 1a)
Summary
Ultraviolet-B (UV-B) radiation can affect several aspects ranging from plant growth to metabolic regulation. Low doses of UV-B mainly induce photomorphogenic changes via the UV-B RESISTANCE LOCUS 8 (UVR8) photoreceptor, while high doses cause damage to biomolecules by the production of reactive oxygen species (ROS) that activate additional stress signaling such as DNA damage signaling, defense and wound signaling, and hormone signaling pathways [8, 9, 13, 34]. These UV-B mediated responses are not mutually
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
